drivers/base: Convert dev->sem to mutex

The semaphore is semantically a mutex. Convert it to a real mutex and
fix up a few places where code was relying on semaphore.h to be included
by device.h, as well as the users of the trylock function, as that value
is now reversed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 5 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index 241b96bcd7ad..6f9619190aaf 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -22,7 +22,6 @@
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/pm.h>
-#include <linux/semaphore.h>
 #include <asm/atomic.h>
 #include <asm/device.h>
 
@@ -404,7 +403,7 @@ struct device {
         const char              *init_name; /* initial name of the device */
         struct device_type      *type;
 
-        struct semaphore        sem;    /* semaphore to synchronize calls to
+        struct mutex            mutex;  /* mutex to synchronize calls to
                                          * its driver.
                                          */
 
@@ -514,17 +513,17 @@ static inline bool device_async_suspend_enabled(struct device *dev)
 
 static inline void device_lock(struct device *dev)
 {
-        down(&dev->sem);
+        mutex_lock(&dev->mutex);
 }
 
 static inline int device_trylock(struct device *dev)
 {
-        return down_trylock(&dev->sem);
+        return mutex_trylock(&dev->mutex);
 }
 
 static inline void device_unlock(struct device *dev)
 {
-        up(&dev->sem);
+        mutex_unlock(&dev->mutex);
 }
 
 void driver_init(void);